Process of and apparatus for producing and consuming gaseous fuel



(No Model.) 2 Sheets-Sheet 1.

J. W. MITCHELL.

PROCESS OF AND APPARATUS FOR PRODUCING AND GONSUMING GASEOUS FUEL.

No. 373,468. Patented Nov. 22, 1887 u I o a a o a o I o n o o u v o n u 0 I a n 0 c u a o Q g g n PETERS. Pholwljflmgnphcr, Washlnglon. D. C.

(No Model.) 2 Sheets-Sheet, 2.

J. W. MITCHELL. PROCESS OF AND APPARATUS FOR PRODUGING AND GONSUMING GASEOUS FUEL. No. 373,468. Patented Nov. 22, 1887.

1 w vbmeooca I (lune/whom UNITED STATES PATENT FErcE.

JOHN W. MITCHELL, OF BAYONNE, NEYV JERSEY.

PROCESS OF AND APPARATUS FOR PRODUCING AND CONSUMING GASEOUS FUEL.

SPECIFICATION forming part of Letters Patent No. 373,468, dated November 22, 1887.

(No model.)

To aZl whom it may concern.-

Be it known that 1, JOHN WV. MITCHELL, a citizen of the United States, residing at Bayonne, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in the Process of and Apparatus for Producing and Consuming Gaseous Fuel; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

My invention relates to an improved process and apparatus for the production and combustion of gaseous fuel.

This process consists, essentially, in to gether injecting superheated steam and liquid hydrocarbon through the wall of a closed firebox or combustion-chamber to a retort, where the steam and oil is decomposed and converted into gas, then discharge the products thus ob tained to the space in the combustion-chamber around the retort, and simultaneously introduce heated air or heated air and superheated steam to supply and maintain combustion, and then burn the gas to heat the retort and to produce heat for generating steam or for other purposes, the products of combustion escaping through the usual flues or passages.

The apparatus consists in the combination of a closed furnace or combustion-chamber, a decomposing-retort, and a superheating-coil arranged within said furnace, a pipe incased within another pipe, constituting an injector for superheated steam and liquid hydrocarbon, and a valved heating-conduit for air, or air and superheated steam for regulating the supply of and for heating the oxygen necessary to maintain combustion.

The apparatus also consists in the combination, in a locomotive-furnace heated by gaseous fuel, of a separate flue for the exhauststeam, so that the escape of the products of combustion will not be affected by said eX- haust described.

It also consists in certain other combinations, hereinafter more particularly described, and pointed out in the claims.

In the drawings, Figure 1 is a vertical longitudinal section through a locomotive furnace and Smokestack. Fig. 2 is a horizontal section through a furnace, showing the inclosed devices in plan. Fig. 3 is a view looking forward, the front of the furnace being removed. Fig. 4 is a front elevation of my improved furnace.

A is the furnace-chamber. The bottom of the furnace is made up of a bottom plate, a, a layer of mineral wool, asbestus, or other nonconducting material, and a covering-plate, a. The plates at and a are firmly held apart by studs a a and tied by suitable bolts. This bottom takes the place of the usualash-pan, and serves to protect the interior of the furnace from the influence of variations of temperature from without.

A is a metal plate which covers the opening to the furnace-chamber, taking the place of the usual door. This plate is tapped for a sight-hole and for the passage of the several fittings, to be hereinafter described.

Bis aremovable decomposing-retort, ofiron, fire-clay, or other suitable material. This retort is supported centrally in the furnacechamber by bars I) 1), corresponding in character with gratebars. Extending from the front wall of the furnace to the retort is a casing pipe or tube, B, and leading through the front wall to this casing-pipe is an injector, consisting of oil-pipes b and surrounding superheated-steam-pipe 0 The oil-pipe leads from a suitable tank or source of supply through a sight-feed cup, I), provided with valve or cut-off by which to regulate the delivery.

c is the steam-pipe, which leads from boiler through the wall into the furnacechamber, where it is arranged, as shown in plan, Fig. 2, resting on the retort B, to form a superheating-coil, c. The superheated. steam from coil is distributed, as shown in Fig. 4, to preliminary burner through branch 0 to injector through branch 0, and to air-supply through branch 0, or to either, as required, the supply being cut off and regulated by a suitable valve in the pipe leading to each of these devices.

D is a perforated tube partly filled with mineral wool to absorb oil,wh'ich I call a preliminary burner. Extending through the wall of the furnace from the oil-supply to this preliminary burner is a conduit, d, 'withwhich the superheated-steam pipe is connected, as

shown in Fig. 4. The oil-supply pipe to this conduit (1 is provided with a sight-feed cup similar to that leading to the injector.

H is an air-conduit provided, by preference, with a bell-mouth and arranged vertically, as shown. This conduit leads through the middle of the metal plate A and the wall of the furnace, where it isdivided laterally and extends to the sides of the furnace, as shown in Figs. 2 and 3, and thence downward, as shown in Fig. 3, and connects with fire-clay perforated tiles H, located on the door around the furnace-chamber, whence the heated contents are horizontally discharged from the sides and back, the currents impinging against each other and distributed throughout chamber A.

A jet of superheated steam through branch 0 is introduced to the air-conduit to force and regulate the supply of air to maintain combustion. The force of the steam and the volume of air are regulated by suitable valves or cut-offs.

The products of the decomposition of superheated steam and oil in the retorts B are discharged through branches 7) b and perforated tubes b b to the combustion-chamber, where they are ignited and consumed to produceheat for generating steam or other purposes, as well as to heat the decomposing-retort and steamsuperheating coil 0. In the locomotive I provide separate lines or passages, E and F, respectively, for the escape of the products of combustion from the furnace and the exhauststeam from the cylinders and pump of the engine, so that there will be no induced draft from the furnace by the exhaust.

G is a perforated disk or lateral brace for staying the steam exhaust pipe within the stack. I

To begin operations with my apparatus, the boiler being supplied with water and the oiltank charged, 1 first admit oil to the preliminary burner and ignite the same by a torch passed through the sight-hole in the metal plate A. The heat generated by the burning oil soon heats the water in the boiler, so that it gives off some vapor, which, passing to the coil 0, is dried or superheated, whence it may be taken through branch 0 to preliminary burner D,where it accelerates the vapori zation andassists in augmenting combustion at this burner. Presently steam will be generated inthe boiler and the retort B will be heated to.a considerable degree. When this occurs, superheated steam and oil in conjunction are injected to the retort in limited and regulated quantities, when gas is generated, which is immediately ignited by the flame from preliminary burner, and which increases the heat of the furnace. During this time air sufficient to maintain combustion has been ad- ,mitted.

In this way the furnace is supplied the heat may be regulated at ,a moderate or high degree, as may be required.

The furnace once started is easily regulated heated before it reaches the combustion-chamberwithout directly reducing the temperature of said chamber. It is observed that for stationary engines or in plants where a supply of cheap gas can be obtained my apparatus may be used for the consumption of such gas alone or in connection with the gas generated in the apparatus without modification or change, a

leading-inpipe connection being made with the casing B,

By providing separate fines for the products of combustion and the exhaust-steam through the stack, and by closing the furnace so that there is neither induced draft nor free admission of air, the gas is completely consumed in the furnace-chamber to produce heat therein without the escape of smell or the production of smoke or refuse, and the expulsion of the products of combustion takes place by reason of their accumulation and pressure from the furnace through the dues and stack.

It is well. known that oil and steam have been decomposed in retorts and immediately consumed for heating metallurgical and other furnaces. It is also known that retorts for decomposing oil and steam have been located in the main combustion-chamber of a furnace. It is also known that the sides or walls of a furnace have been perforated for the admission of air previously heated. It is also known that superheating coils and pipes have been arranged within the walls of a furnace, and it is also known that mineral wool has been used as a wick or vehicle for holding burning oil. I do not, therefore, claim any one of these devices or any group of devices for performing any one of the functions referred to; but

What I do claim is- 1. The combination of a closed furnace or combustion-chamber, a retort within said combustion chamber, and a superheating-coil within said furnace, an injector for superheated steam and oil communicating with the retort, a valved conduit for conducting air, and a conduitof perforated tiles or pipes surrounding and within the combustion-chamber for heating the air and for discharging the same laterally to the chamber, as specified.

2. The combination, in a furnace for generating and consuming gaseous fuel, of aretort, a superheating-coil, a preliminary burner, and a conduit or passage around the interior walls of the furnace for heating the air, substantially as described.

I IO' 3. The combination, in a gaseous-fuel furnace, of a retort, a snperheating-coil, and conduit or passage extending around the furnaceeharnber, all within the main furnace-chamber,

5 substantially as described.

4. The combination, in a gaseousfuel furnace, of a retort, a preliminary burner, and an annular or surrounding passage for heating air within the main furnacechamber, asu'perheating-coil, and valved branch pipes leading to from the steam-snperheater to said retort, preliminary burner, and air-conduit, as specified. In testimony whereof I affix my signature in presence of two Witnesses.

- JNO. W. MITCHELL. Witnesses:

WM. M. STOOKBRIDGE, J. LEEDE. 

